List branches and tags from a repo

[Wauplin]

Resolve #1260 (cc @antoche).

List branches, tags and "converts" from a repo on the Hub. Implemented, tested and documented the list_repo_refs method + RepoRefs data structure.
I did not document extensively what the convert ref is as I don't expect much usage of this in hfh (see docs)

>>> from huggingface_hub import HfApi
>>> api = HfApi()
>>> api.list_repo_refs("gpt2")
RepoRefs(branches=[RefInfo(name='main', ref='refs/heads/main', target_commit='e7da7f221d5bf496a48136c0cd264e630fe9fcc8')], converts=[], tags=[])

>>> api.list_repo_refs("bigcode/the-stack", repo_type='dataset')
RepoRefs(
    branches=[
        RefInfo(name='main', ref='refs/heads/main', target_commit='18edc1591d9ce72aa82f56c4431b3c969b210ae3'),
        RefInfo(name='v1.1.a1', ref='refs/heads/v1.1.a1', target_commit='f9826b862d1567f3822d3d25649b0d6d22ace714')
    ],
    converts=[],
    tags=[
        RefInfo(name='v1.0', ref='refs/tags/v1.0', target_commit='c37a8cd1e382064d8aced5e05543c5f7753834da')
    ]
)

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[LysandreJik]

Very clean PR, love it!

[LysandreJik]

Smart to only define it on the setUpClass for it to act on all subsequent methods. I wonder if it wouldn't be cleaner to put it on the class itself so that it's very clear that it should affect the entire class?

[Wauplin]

Actually I did that as a workaround because

@with_production_testing
class ListRepoRefsTest(unittest.TestCase):
    @classmethod
    def setUpClass(cls):

was not working for me 😢
But I have to admit my debug time on that was approximately 30s, just the time to try some possibilities and take the first one that worked 🙄

[LysandreJik]

Haha in that case we can also keep it there, it was just a nit, to be fair.

[julien-c]

just left a small nit on naming

[julien-c]

you're not just overriding the init from dataclass?

[julien-c]

(dont remember the best practice in Python dataclasses)

[Wauplin]

Yep why not. Best practice depends on your use case I guess.

Here the GitRefs will never be initialized by someone else than use from server-side data so it makes sense to put it in the init. It's not good practice when you force the users to have your data format as input instead of letting the default dataclass constructor. (at least IMO)